UE4UDP使用虚幻API的组播详细案例

以下是使用虚幻引擎API进行组播的详细案例：

1. 首先，您需要创建一个新的虚幻引擎项目，并打开C++代码编辑器。

2. 在您的项目中创建一个新的Actor类，例如MyUDPActor。

3. 在MyUDPActor.h文件中，添加以下代码：

#include "MyUDPActor.generated.h"

UCLASS()
class MYPROJECT_API AMyUDPActor : public AActor
{
    GENERATED_BODY()

public:
    AMyUDPActor();

    virtual void BeginPlay() override;

    void StartUDPReceiver(const FString& YourChosenSocketName, const FString& TheIP, const int32 ThePort);
    bool StartUDPReceiver(const FString& YourChosenSocketName, const FString& TheIP, const int32 ThePort);

    void StopUDPReceiver(const FString& YourChosenSocketName);
    bool StopUDPReceiver(const FString& YourChosenSocketName);

    bool UDPSocketSender(FString YourMessage, const FString& TheIP, const int32 ThePort);

    FSockAddr RemoteAddr;

    FUdpSocketReceiver* UDPReceiver = nullptr;
};

4. 在MyUDPActor.cpp文件中，添加以下代码：

#include "MyUDPActor.h"
#include "Networking/Public/Networking.h"

AMyUDPActor::AMyUDPActor()
{
}

void AMyUDPActor::BeginPlay()
{
    Super::BeginPlay();

    FString IP = TEXT("127.0.0.1");
    int32 Port = 10001;
    FString SocketName = TEXT("MySocket");

    StartUDPReceiver(SocketName, IP, Port);
}

bool AMyUDPActor::StartUDPReceiver(const FString& YourChosenSocketName, const FString& TheIP, const int32 ThePort)
{
    GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Yellow, TEXT("UDP Receiver started!"));

    UDPReceiver = new FUdpSocketReceiver();
    FIPv4Endpoint Endpoint(FIPv4Address(0, 0, 0, 0), ThePort);
    TSharedRef<FInternetAddr> Addr = Endpoint.ToInternetAddr();
    Addr->SetIp(*TheIP, true);

    int32 BufferSize = 2 * 1024 * 1024; // 2MB buffer size
    UDPReceiver->Init(BufferSize);

    UDPReceiver->Start();
    UDPReceiver->OnDataReceived().BindUObject(this, &AMyUDPActor::UDPSocketListener);

    return true;
}

void AMyUDPActor::UDPSocketListener(const FArrayReaderPtr& ArrayReaderPtr, const FIPv4Endpoint& EndPt)
{
    FString ReceivedData = FString(UTF8_TO_TCHAR((const char*)ArrayReaderPtr->GetData()));
    GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, ReceivedData);
}

void AMyUDPActor::StopUDPReceiver(const FString& YourChosenSocketName)
{
    GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Yellow, TEXT("UDP Receiver stopped!"));
    if (UDPReceiver)
    {
        UDPReceiver->Stop();
        delete UDPReceiver;
        UDPReceiver = nullptr;
    }
}

bool AMyUDPActor::UDPSocketSender(FString YourMessage, const FString& TheIP, const int32 ThePort)
{
    TSharedRef<FInternetAddr> Destination = ISocketSubsystem::Get(PLATFORM_SOCKETSUBSYSTEM)->CreateInternetAddr();
    bool bIsValid;
    Destination->SetIp(*TheIP, bIsValid);
    Destination->SetPort(ThePort);

    if (!bIsValid)
    {
        GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, FString::Printf(TEXT("UDP Send: Invalid IP address %s"), *TheIP));
        return false;
    }

    int32 BytesSent = 0;
    FString Message = YourMessage + TEXT("\n");
    TArray<uint8> Data = TArray<uint8>((const uint8*)TCHAR_TO_UTF8(*Message), Message.Len());
    FSocket* SenderSocket = FUdpSocketBuilder(*YourChosenSocketName).AsReusable().WithBroadcast();

    bool bDidSend = SenderSocket->SendTo(Data.GetData(), Data.Num(), BytesSent, *Destination);

    if (bDidSend)
    {
        GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Green, FString::Printf(TEXT("UDP Send: Sent %d bytes to %s:%d"), BytesSent, *TheIP, ThePort));
    }
    else
    {
        GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, FString::Printf(TEXT("UDP Send: Unable to send packet to %s:%d"), *TheIP, ThePort));
    }

    SenderSocket->Close();
    delete SenderSocket;

    return bDidSend;
}

5. 现在，您可以在其他Actor类中使用MyUDPActor的实例来发送和接收UDP数据包。例如：

AMyUDPActor* MyUDPActor = GetWorld()->SpawnActor<AMyUDPActor>();

MyUDPActor->UDPSocketSender(TEXT("Hello World!"), TEXT("127.0.0.1"), 10001);

这将向IP地址为127.0.0.1，端口号为10001的地址发送“Hello World！”消息，并在MyUDPActor的屏幕上显示该消息。